Improvement in hot-blast stoves



UNrrEn Stearns Arum? BENJAMIN FORD, OF MIDDLEBOROUGH-ONTEES, ENGLAND.

IMPROVEMENT IN HCT-BLAST STOVES.

` Specification forming part of Letters Patent No. 124,803, dated March 19, 1872.

To all whom it may concern:

Be it known that I, BENJAMIN FQRD, of Middleborough-on-Tees, England, have invented a new and useful lmprovement in Hot-Blast Stoves; and l do 4hereby declare that the following is a full, clear, and exact description of the same, reference being had to the'accompanying drawing forming part of this speci`` cation, and in which- Y Figure 1 represents a vertical longitudinal section of a hot-blast stove constructed in aci cordance with my invention, and as designed to beheated'by the waste gases ofa furnace; Fig. 2, a vertical transversev section in part thereof' at the line w .fr in Figs. '1 and 3 Fig. 3,

aI horizontal section of the same at the line y y in Figfl; and Fig. 4, a vertical longitudinal section in part, and upon alarger scale, showling the base portion of two of the stand-pipes in part, as fitted to their places in a detached or separate base box. Fig. 5 is a vertical longitudinal section of a like construction of hotblast stoves as heated by the products of combustion from a fireplace or series of lireplaces at its one end.

Similar letters of reference indicate correspondin g parts throughout the several figures of the drawing.

My inventionconsists in a hot-blast stove made up of a series of flat stand-pipes of novel construction, and arranged so as to form a wall running in direction of the iiow Vof the heated gases within a chamber or casing through which saidwgases pass on both sides of the wall of pipes, the stove being composed of a series of such walls and inclosing chambers,

forming stove sections, and arranged side by side, and the pipes being iitt'ed into or resting 0n separate boxes at their base, and the roof ofthe chamber being fittedwith separate boxes over the stand-pipes. The gas, entering at the hot end, iiows horizontally1 along the faces of the pipes into vertical flues at the cold end, the gas traveling against the blast, which ascends and descends the pipes.

By my improved construction there is an increased efficiency in heating the blast; `the stove is less liable to get out of repair consequent upon expansion and contraction, or from other causes; the facility for repairs and cleaning is enlarged; and the cost of lirst erection erected within each chamber A, one in rear of the other, so as to form a wall of pipes exposed to the full action of the gases on and around them, and being free at their upper ends; also of a dat construction, so as to present their broad sides to the direct action of the gases or flame and heated currents in directions parallel or thereabout with the course of the gases through the chamber, and so that said gases cover their whole surface equally on both sides. Thus constructed' and arranged the whole area of the pipes is made an elfective heating surface. Said pipes, too, are close ly incased by the lire-brick walls of the charnber in which they stand, thereby keeping the llame and heated currents close tothe surface ofthe pipes. These brick walls soon become incandescent, and act as effective radiators and reflectors of the heat to the parallel broad surfaces of the pipes. The hot gases are ad; mitted from above through a valve, C, intoa vertical combustion-chamber, D, at the one end of the structure, and pass through vertical elongated side openings b b into the chamber A, for travel therethrough and among the pipes B B, finally passing out through similar openings c e to the chimney Eror down draught, if

preferred. The cold blast to be heated is admitted by a pipe, F, at the upper portion of the opposite end of the structure, and caused to descend within the chamber A and' to en ter vthe first of the boxes Gr G, on which the p pipes B B stand.` Said ptpes have an arched division, d, at their base, terminating in or forming part `of a vertical partition, c, which stops short of the top ofthe pipe, and on either side of this partition are other parallel diaphragms or partitions f f arranged in close proximity to the top of the pipe, but stopping Frrcn.

short of its base. Each pipe B stands upon and communicates with t-wo adjacent base-boxes, and has its divided foot incased by rings g g, and secured by luting. The cold blast, entering the rst base-box G ofthe series, passes up the two nearest vertical iiues formed by the diaphragms in the pipe, and down the two more distant iiues thereof, and from thence into the next box B, and up and down in a similar manner the next pipe in the series, and so on in succession throughout t-he whole series of baseboXes and pipes. and finally passing upward and out by a pipe, H, at the hottest end of the chamber. The dotted arrows in the drawing indicate the course of the heated gases, and the arrows in full lines the course ofthe blast.

From this description it will be seen that the greater part of the connections, which in other stoves are on the outside, in this arrangement are kept inside, and instead of operating to cool the blast act as heating surfaces. It is preferred to construct the stove in at least eight sections, and to divide the necessary blast for a single furnace up among them, admitting the same by pipes of large sectional arca compared with the quantity of blast passing through them, whereby the blast passes more slowly and remains longer under the action of the heat. The friction of the blast, also, in passing through the stove, is reduced to a minimum, and little or no difference of pressure exists at the tuyere.

The roof of the stove is fitted with a series of separate boxes, I I, containing brick llin g, and arranged over the stand-pipes B B to allow of the lifting out of any one of said pipes and inserting another when necessary, by merely cutting the ring that makes the joint of the boz'r and removing its brick filling. By this provision the pipes, or any interior portion of the stove, can be taken out and replaced Without destroying the main brick work, and in an incredibly short space of time, and with but little labor; also, any one section be thus opened for repair without interfering with the other sections of the stove or materially impairing the action of the latter. A hot-blast stove constructed as described, however, is but little liable to get out of repair, inasmuch as the pipes B B are equally heated, consequently subject to equal` expansionand contraction, and free from straining and bending, being free at their upper ends, thus preserving the integrity of the stove and preventing break or loss of blast atthe joints. Said pipes, too, are

constructed without a bend at their tops, consequent] y they are less liable to accident, and having a large sectional area and being braced by three or more diaphragms each, an efcient heating surface is obtained, combined with great strength of pipe. Furthermore, the number of pipes is diminished.

rl`he saine advantages which accrue to the repairing-of the stove when constructed as described apply with equal force as regards facility to the cleaning of it, nor need the stove be stopped or cooled down for either purpose; also, room is afforded for workmen on the inside of a section. The stoppage of a stove for either of such purposes is a great drawback in the manufacture of iron by hot-blast, and is lia-ble to damage the stove.

Lastly, the cost of erection and the working expense of a stove constructed as described is reduced, the quantity of cast-iron, which is the most expensive item, being very small 5 and yet a higher temperature may be attained with perfect safety than is practicable with metal stoves generally. The economy of fuelis greater, because the products of combustion must pass along the Whole surface of the pipes, and the heat be taken up by the blast before said products reach the chimney.

Fig. 5 of the drawing shows a similar construction of stove heated by a lire-place or series of lire-places, J arranged below.

What is here claimed, and desired to be secure by Letters Patent, is-

l. The combination of the nat stand-pipes B, left free at their upper ends, with the chamber or casing A, when arranged to form a wall running in direction of the length of said chamber, substantially as specied.

2. The combination of the separate baseboxes G with the stand-pipes B, the inlet blastpipe F, and outlet blast-pipe H, the chamber A, and its inlets b and outlets c, essentially as described.

3. The combination of the upper boxes I with the separate stand-pipes B and their baseboxes G, substantially as specified.

4. The independent stand-pipes B, of a flattened construction, and providedwith three or more vertical diaphragns, c and f, Ain combination with the base-boxes F, essentially as herein set forth.

BENJAMIN FORD.

IVitncsses:

WM. GOWARD, F. H. BENNETT. 

